Theresa May’s political career has been marked by a low-key style and dogged determination, both qualities stemming from the strong sense of duty forged in her childhood.
Oxford-educated and a life-long Conservative, Mrs May's early years were spent in the seaside town of Eastbourne, where she enjoyed a sheltered upbringing as the only child of a Church of England clergyman.
In comparison to many of her Conservative colleagues Mrs May attended state schools rather than the expensive private institutions steeped in history that many of her predecessors went to.
Gaining a degree from Oxford fitted more into the tradition of UK leaders, but her subject choice of geography was not the typical breeding grounds for a prime minister even if she then spent six years working for the Bank of England.
The early 1980s were marked by tragedy when her father died in a car accident and her mother from multiple sclerosis.
Aged 25 and finding her place in the world, she was now alone. Mrs May has previously commented she was sorry her parents never saw her elected as a Member of Parliament – but they didn't even witness her role tenure as a Conservative councilor for the London borough of Merton from 1986 to 1994.
Helping her through the tragedy was her husband Phillip, who she married in 1980 at the age of 23 after meeting at Oxford University. He is often described as her "rock." Mrs May had an eclectic group of friends whilst studying, including Sir Alan Duncan and Damien Green, who would later become ministers and close allies.
Benazir Bhutto, the future Pakistani prime minister and a high-profile member of the Oxford student body introduced her friend Theresa to Phillip.
In her early parliamentary career, after being elected for the new constituency of Maidenhead in 1997, one her most notable roles was as the first female chairman of the Conservatives. She famously urged the party to change, uttering the words: "You know what people call us -- the Nasty Party."
When David Cameron became prime minister in 2010, he immediately made Mrs May home secretary. Arguably her biggest test was the 2011 summer riots, when a London man was shot dead by police, sparking country-wide chaos.
Elevated to the prime minister's position in the aftermath of the June 2016 referendum, Mrs May set out a series of principles to forge Britain's post-Brexit position that included quitting both the EU's single market and its customs union. Those red lines made her own task of coming to an agreement with Brussels much more difficult.
After calling a general election that lost the Conservative majority Mrs May inherited from David Cameron in 2017, her closest advisers were forced to quit. That left the prime minister politically vulnerable to both internal and external events.
The new term has been marred by instability driven by the pressures of negotiating Brexit ahead of a deadline that expires in March 2019.
Cabinet ministers have quit in regular succession and Mrs May's government became the first administration ever to be held in contempt of parliament earlier this month.
Comparisons are being made between Mrs May’s predicament and Malcom Turnbull, former Australian prime minister - and another Oxford friend.
He faced a leadership crisis earlier this year in his Liberal party. He survived the initial vote, but amid further pressure only ten days later he handed in his resignation.